Opisthias
Encyclopedia
Opisthias is a Late Jurassic
genus
of sphenodont reptile from the Morrison Formation
of western North America
, present in stratigraphic zones 2 and 4-6.
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of sphenodont reptile from the Morrison Formation
Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish...
of western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, present in stratigraphic zones 2 and 4-6.
See also
- Prehistoric reptilePrehistoric reptileThe term prehistoric reptile covers a broad category that is intended to help distinguish the dinosaurs from other prehistoric reptiles. As the dinosaurs, because of their long and successful reign for many millions of years, are almost exclusively dealt with in their own category of prehistoric...
- Paleobiota of the Morrison FormationPaleobiota of the Morrison FormationThe Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has a wide assortment of taxa represented in its fossil record, including dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and...